Thomas w



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CARBURETER.

APPLICATION FILED D CT. i6 191?.

1,3,fi v Patented Dec. 28, 1919.

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Specification t Letters Patent.

Patented nee. 2s, iota.

Application filed October 1.6, 1917. Serial no. 196,943.

To all whom it may concern:

Be it known that I, THOMAS W. Born, a a citizen of the United States,anda resident of Stoneham, county of Middlesex, and State ofMassachusetts, have invented an Improvement in Carbureters, of which thefollowing is a specification.

This invention relates to that class of carbureters known as suctionteed carburetors, or. those in which the liquid ruel is lifted from alow level tank to the oarbureter by the suction action of the engine, ormotor.

While various types of carburetors of this class have been produced,they are, so far as I am aware, objectionable in that they involve theuse of automatic valves, such "as float and check valves, auxiliarytanks and other devices, all of which add materially to the cost ofmanufacture, and some of which require careful adjustment, and areliable to get out oi. order or require frequent readjustment. Moreover,these devices are, so far as I am aware, adapted to position only, i. a,the upright position, and are practically inoperative in any' otherposition.

The object of my invention is to produce a suction feed carbureter whichis adapted for practically all conditions of use which may he demanded,which will effectively mix the liquid'fuel with the air, and apdesiredrelative proportion of air and vaporized iuel under all variations inthethrottle opening, so that high efiiciency may be secured, and,further, to produce a carbureter which is oi. such simple constructionthat it may be made at a relatively small expense and which makesunnecessary the employment of automatic valves, such as float valves andcheck valves.

1 accomplish these objects by the means shown in the accompanyingdrawing in which 7 'Figure l is a plan view of a carbureter" embodyingmy lnvention.

Fig. 2 1s a sectional view, at line 22 of Fig. 1.

Fig. 3 is a device.

Fig. i is a sectional view at line 4-4: of Fig. 2. v

i Fig; 5 is'a side view, and

Fig. ncctions.

.ment being preferable, count oi convenience in I versely, in suchaposition p 11 and is provided view of the suction end of the extendsthrough 6 is a view showingthe tank con As shown in the drawing, thecarburetor casing is composed of two tubular SGCtlOHf-l 8 and, 10 whichare provided with abutting flanges connectedby screws 9,'thisarrangeprincipally, on acassemblin the purposes of the invention, t ecasing members 8 and 10 will be considered as a single casing, one endof which, (the outer end of member 10) is designed to be connected tothe engine or motor, end of which is open to the atmosphere.

and the other i but, tor

According to my invention an aperture 11 is bored entirely through thecasing, transthat the center passage throughthe casing at right angles,and also lies in the plane of contact of the casing members 8 and 10.

A plug 12 is threaded into said aperture tral passage 14, the outer endof which is chambered and threaded to receive the end of the supply pipe16, which is connected thereto, and is extended downward to the bottomportion ofa vented low level supply tank 'l8,to which it is alsoconnected, as indicated in Fig. 6. The inner end of said plug is taperedor flared to provide a seat for a needle valve 20, as hereinafterdescribed.

A tube 22 is closely fitted and rotatably and slidably mounted in theaperture 11, said tube being arranged to extend across the passagewaythrough the casing,,so that its ends bear at opposite sides of saidpassageway. The opposite end from the plug 12 is rigidly connected to atube 24, the latter being inserted therein so that the end oi the tube22 may act as a shoulder. The tube 24 is slidably and rotaof said tube22,

with a longitudinal cen-p tably'movable in the bore of a plug 26,

formed by the adjacent endof tube 22. A

cap nut 30 is threaded on the outer end of the tube 24 and the stem ofthe needle valve and is threaded in said nut and in the outer end of thetube 24',

' so that, by rotating the necdleyalveby its handle 21, its positionwith relatiomtoits seat in the end of the plug l21nay1bo varied. Thescrew threads between the nut SO adjusted.

and the exterior of the. tube 2& have a different pitch than thosebetween'the shank of the needle valve and .the nut and the iiiterior ofsaid tube, so' that, to adjust the needle valve, it is necessary to holdthe nut from turning in a position in which the needle valve may beturned freely to the desired point. When this has been done the nut isreleased, and the needle valve is turned in slightly, immediatelycausing the threads to j am, so that the needle valve will be securelylocked against becominig unscrewed or moved out of the position to whichit was I A cam 32 is rigidly secured on the tube 24:, between the nutand the outer end of plug 26, and correspondingly inclined faces [areformed on the adjacent sides of said cam and plug, so that, whenthe camis r0- tated from its initial position, shown in Fig. 4, the needlevalve will be drawn away from its seat. An arm 34 is formed integralwith.

the cam 32, to which the throttle operating means isconnect'ed.

A throttle valve 36, of the butterfly type,

is rigidly mounted on the tube 22, within the casing passage, and anannular, internalrib 38 is formed within said passage, whichsubstantially reducesorconstricts the area thereof at this point and theopposite sides of which provide seats for the opposite portions of thethrottle valve. It will be ap parent'that, when the tubes 22 and 24 arerotated by arm 34-, the valve 36 will be opened orclosed.

An opening 22 is formed in the side of the tube 22, at the side of thethrottle valve which, when closed, faces the suction side 10 of thecarbureter casing, or portion of the casing which is connected to theengine,

' said opening beingnearly as large asit is practicable to make it,extended nearly half way about the tube and lengthwise thereof,

.- throughout nearly the entire diameter of the .screen 4.0 the meshespassage portion inclosed by the inner edge of the rib 38. Said openingis covered by a of which are preferably very fine.

v The air intake end of the casing may be justed so that, when thethrottle valve is closed, the needle valve will'be held in con tac'twith its seat on the end of plug 12, or it is adjusted to permit aslight leakage,

sufficient to run the engine without any load,

the latter adjustment being preferable under most conditions. I As thethrottle valve 36 is swung from closed position by the arm 34, the cam32 will ride on the cam face 26 on plug 26, causing the tubes 22 and 24(which, for the purposes of the invention, may be considered as a singlecontinuous tube), to be moved longitudinally outward,

so that they will carry the needle valve away,

from its seat -on the end of the plu 12.

This movement will cause the valve 36 to be valve to be moved backtoward its seat by the action of the spring 28 on the tube, 22. With theabove described construction, when the engine is to be started,if theneepermitted past it when the throttle valve is nearly closed, it may ormay not be necessary to open the throttle valve slightly be forestarting the engine, according to conditions. In any case these valveswill perdle valve is adjusted so that a slight flow is r mit leakage tosome extent' The air )rc'ssure in the portion ofthe carburete rcasingdlrectly connected to the engine, will be immediately reduced,when the engine isturned over, so that atmospheric pressure on thesurface of the fuel in the tank 18' will cause the fuel to be forced upthrough v the pipe 16 past the needle valve, and into the tube 22 andthen through the screen 40 into the casing, to which it will bedelivered in atomized form.

When the throttle valve is moved to increase the fuel supply to theengine, the needle valve will be correspondingly moved, so that, as theair is drawn past the throttle, it will be mixed with the atomized fuel,as it is discharged through the screen 10, the quantity of fueldischarged being determined by the adjustment of the needle valve.

As the fuel must pass through the screen 40 before it is delivered tothe casing, all drops or globules of it will be broken up into a finelydivided state, so that the air" and liquid will be thoroughly mixed, orthe liquid will be effectively vaporized.

As the passage through the carburetor casing tapers, from the air inletend to the port formed by rib 38, and then is gradually increased insize from said port, a. Venturi tube is formed thereby which inateriallyaugments the suction action of the engine at. the screened discharge.opening. so that the effective suction action of the engine issufficient to cause the fuel demands of the engine to be met under allconditions,

the quantity delivered being determined by the adjustment of the needlevalve.

\Vith the above described construction, not only is the volume of airdrawn past the throttle valve varied accordingly to the extent to whichit is opened, but the parts are so constructed that the extent towhich'the needle valve is opened is also varied in coressary to producean efiicient explosive mix ture, will be delivered to the 'carburetingchamber, in all open positions of the throttle valve. It will be obviousthat thepitch of the cams and the relative sizes of the inlet anddischarge ports are matters of design. For example, by varying the pitchoftthe cam at different points, the desired proportion of air and gasmay be varied for different speeds, or extent ofopening of the throttlevalv y All the advantages of a vacuum feed carbureter, as well as of anordinary gravity feed carbureter, are thus secured, with the abovedescribed constructiom without many of the well knownattendantdisadvantages of such devices. The present device ma esunnecessary the use of either a float valve or an air inlet check valve,both of which-re get out of order;

1. A carbureter comprising a casing having an air passage and .a liquidfuel supply passage leading thereto, a throttle valve for controllingsaid air passage, a stem for said valve, a needle valveextendinglongitudinally of said stein in position to control said fuelsupply passage, and having a threaded connection with said stem, topermit adjustment thereof with relation to the stem, and means to causesimultaneous rotational and longitudinal'movement of said stem to movesaid throttle valve rotatably, to control said quire careful adjustmentand are liable to air passage, and to move said-needle valvelongitudinally to control said fuel supply passage in correspondingrelation.

3.. A- carbureter comprisin 2. '-:A- carbureter comprising a casinghav-" ing an air passage, and'aflfuel supply passage opening to saidairpassage, a throttle valve for controlling said air passage, a stem forsaid valve mounted for rotational and lon itudinal movementsinthe'casing, a ne e valve extending longitudinally of said stem in positionto control said fuel sup ly passage, and having a threaded connectionwith w said stem to permit longitudinal adjustment thereof with relationto the 'stem, means to rotate said stem to control said throttle valveand means, including a cam, to, move said stem longitudinally in onedirection or the other, according to the direction in which 'it isrotated, to move saidneedleyvalve in directions: to vary the fuel supplyin pro portion to the extent to is varied.

ing anxair passage leading theret a tubular'stem-extendin'g transverselyof said. passage and having a butterfly valve mounted thereon, =1 liquidfuel supply pipe having an alinement with said stem, a needle valveoutlet opening into said casing, in axial axially disposed withinsaid-stem in position to control the flow from said 'openlng and Ihaving a threaded connection with said stem, to permit adJuStmentthereimmeans to rotate said stem,and means, including a cam,

for moving said stem. longitudinally as'it is rotated to vary the airand fuel supply correspondingly.

In testimony whereof, I have signedmy 7 5 name to this'specification.THOMAS'W. onn.

Witness:

LOUIS H. H'ARRIMA'N.

which the airsupply I a casing haV- 69

